Demotech, design for self reliance


Search for

All Designs

On this page you can find photo series on how to construct certain applications as well as photo series of more genral nature. This section is still under construction, but feel free to look around.;

Translate
Copyright & Open Source

Creative Commons License
This work is licensed under a Creative Commons Attribution-Share Alike 3.0 License.

Please refer to our work and provide us with usefull feedback and comments on our design initiatives.

Liability clause

We cannot be held accountable for injuries incurred during construction or usage of our designs and construction manuals.

The Hy2U-Story



A story about the coming into being of a device for washing hands in Maastricht's Demotech Lab and in a little village in Ghana

By Reinder van Tijen,
Demotech, design for self-reliance,
Maastricht,
The Netherlands


date: September 10, 2007

The need and the reality
In Ghana, hand washing is a highly valued tradition and is taught to children in primary school. But water can be scarce and often has to be hauled from far away.
For washing hands? Yes!
This school on an island in the Volta region only had these two buckets of dirty wash water available for the class. Sadly, with no indoor plumbing, the hygiene instruction can unintentionally transport bacteria from child to child, which can spread diarrhea and other intestinal illnesses.
The innovation and the research
The first prototype of a simple device for hand washing used a green plastic 20-liter jug with the top cut off. A valve controls the water passing through a hole punched in jug’s bottom. You simply push the valve up a bit and a stream of water flows out onto your hands: ideal for washing them!
The students that had traveled
Lisa, and another member of the Student Workforce, Julie, knew from experience about the problem of washing hands without running water. They wanted to take the new device to Ghana, during their upcoming visit in the summer of 2007. I jumped at the opportunity to finally field-test the hand-washing device. We started to reduce the obstacles of cost and complexity from its design, so the girls could more easily introduce it. Instead of the not-for-free plastic jug, I made a big strong bag from thick plastic sheet material. Transparent, it looked nice!
Lisa remembered the thin plastic bag, flying everywhere
Then Lisa remembered from her year long stay in Ghana the so called "rubber bags". Such bags were handed out by vendors at the market. Soup was also sold in it, showing such bags could hold water without leaking. Such bags are also used the Netherlands for the same purpose.
Result: I asked the girls to sew a cloth bag same size as the plastic bag as to give it support and protect the plastic against punctures. At the bottom of the cloth bag I fitted a wooden board with the self-closing valve.
So the Hy2U was born
This name is kind of an SMS-type writing, meaning “a salute to you”, or, when understood more meaningfully: the wish of 'hygiene to you'.

And then we realized the Hy2U could also be made specially nice looking, that people would like to display in their homes. This was a good start, but its real beauty was soon to come!
Completing the design
Work at the Demotech Lab in the Netherlands continued with a search for the finishing touch: a basin to collect the spill water and drain it away.
Julia traveled to Ghana
At that time Julia packed the latest prototype of the Hy2U and traveled to Ghana. Here she is on-board the boat that took her to one of the islands formed in the Volta dam lake. She was about to make a big success of her trip!
Ghana people discover how it works
Upon arrival Julia asked people to have a good look at it the Hy2U as she showed them the trick of the self-closing water valve. Indeed, there was plenty of interest. She planned to demonstrate its practicality by testing it at the local primary school.
How the valve works
From the inside of the "rubber" polyethylene bag, you can see how it is secured to the board and to the valve seat. Red string to slots cut into both ends of the bottom board keep the bag in place and hold the rubber string that presses down on the valve in the middle.
The big trick is that you can open the valve by pushing up on the other end of a wooden pin (the valve stem) that sticks out from under this board.
The 'rubber' bag
This picture explain better how the "rubber" bag is connected to the board. This connection has to be done is a way as not to puncture the very thin polyethylene. This connection takes a lot of care. Therefore it was further developed to get it done with less risk for such punctures.
The picture shows the wooden valve tube that is inserted in the middle of the wooden board. The end of the valve stem just sticks out of this valve tube.
The valve tube
The end of the valve stem just sticks out of this valve tube. With this end you had to pierce the polyethylene sheet that covers the the mushroom like top of the valve tube after (renewed) attaching it to the valve seat on the other side of the board.
The plastic that covers the valve seat becomes the ideal lining for the little valve disk cut from a flip-flop toe slipper.
The good functioning of the Hy2U depends on very careful design work to get get this crucial valve function properly!
First use in Ghana
Now the school that had only the two buckets of dirty wash water has a more hygienic alternative. The Hy2U uses very little water: 100 to 150 children can wash their hands with a Hy2U bag filled with five liters of water.
Boys and girls started using it
Boys and girls started using it. Though the Hy2U is unlike anything they knew, specially these kids liked it. Julia reported immediate understanding of the use. That is good for a start!
Made in Ghana!
Julia then invited people to start to make more Hy2U's as there was plenty opportunity for further use. People came with that idea to use a bigger size "rubber" bag. Then it would be very suitable for bathing at home.
Preparing valves
Since the Hy2U was carefully designed for local manufacture in situations like those found in Ghana, copying the Hy2U was not difficult to start up. The required woodworking skills did not pose any problems: the crucial valves were produced as if it were a routine job.
Sewing the bags
Sewing the cloth cover was done with an easy smile. Nicer looking cloth was used and indeed people decided to make a bigger size bag, to contain more water.
The fun of cooperation
The fun of cooperation came in welcome when it was time for the rather complicated attachment of the rubber bag to the wooden base with its valve seat. Effectively cooperating hands did the job.
Big bag taken in use
The Hy2U with the bigger bag was demonstrated to the public. This lady is clearly aware of the missing spill water basin and something to collect the drips. Julia is in contact with these people and we will show them how to make the Hy2U complete to solve this problem.
What count is clean hands
What matters most is that these little hands are now safe hands: safe for handling food and safely guarded against common diseases to a far larger degree than when easy hand washing was still a problem.
The fun and the future
Since we are in Ghana, and since kids love music and drumming, a second use for the valves was soon discovered!
Demotech's task
Now I regard it as Demotech's task to make sure the Hy2U becomes really beautiful. The two to three billion people, -about half the world's population- that miss piped water in their homes, deserves a beautiful looking compensation. We will ask users to apply locally woven fabrics, We will propagate the Hy2U to be decorated like so many other objects as made looking real nice.
Also see the The Beauty Contest
WHO takes care?
May we regard the future as a nice person that takes good care of the need of hygiene for these kid's hands?
The number of hands that need proper care is huge, is a billion hands a good guess? The World Health Organization seems to think so. Study these links to get convinced:
- http://www.who.int/patientsafety/events/05/HH_en.pdf
- http://jama.ama-assn.org/cgi/content/full/291/21/2547?maxtoshow=&HITS=10
More links, more info
Citing this study:
According to WHO, 1.8 million children die every year from diarrhoeal diseases and 90% of those are aged less than five years, mainly in developing countries. The study's findings suggest that half of those lives could be saved.
The Hy2U-Campaign
So Demotech is in good company in campaigning for and promoting hand washing. This is the reason to launch as soon as possible the ....
Hy2U-campaign
Follow the news on the Hy2U campaign posted on Demotech's campaign website:
http://www.hy2U.org

or email us at:
info@demotech.org